Bioenergetics and BiochemicalReaction TypesS-1421.Entropy Changes during Egg DevelopmentConsider a system consisting of an egg in an incuba-tor. The white and yolk of the egg contain proteins, carbohydrates, and lipids. If fertilized, the egg istransformed from a single cell to a complex organism. Discuss this irreversible process in terms of theentropy changes in the system, surroundings, and universe. Be sure that you first clearly define thesystem and surroundings.AnswerConsider the developing chick as the system. The nutrients, egg shell, and outsideworld are the surroundings. Transformation of the single cell into a chick drastically reducesthe entropy of the system (increases the order). Initially, the parts of the egg outside the em-bryo (within the surroundings) contain complex fuel molecules (a low-entropy condition).During incubation, some of these complex molecules are converted to large numbers of CO2and H2O molecules (high entropy). This increase in entropy of the surroundings is larger thanthe decrease in entropy of the chick (the system). Thus, the entropy of the universe (thesystem surroundings) increases.2.Calculation of Gfrom an Equilibrium ConstantCalculate the standard free-energy changefor each of the following metabolically important enzyme-catalyzed reactions, using the equilibriumconstants given for the reactions at 25 C and pH 7.0.

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